Both lawmakers alluded to Harris’s debate showing in praising her presidential chops.

"Before the debate, Kamala Harris's viability as a candidate had been extremely underestimated, in part because voters are still getting to know her," Wilson told The Hill.

Wilson also praised Harris for the manner in which she challenged Biden when she directly confronted the former Delaware senator over his opposition to federal efforts to bus students across school districts in the 1970s.

In a poignant moment, Harris said that she had been one of the children to benefit from the busing policies intended to racially integrate schools.

"At last week's debate, the rest of the world saw the formidable candidate that I've always known her to be. In her handling of Vice President Biden, she was respectful but commanding, and her recollection of being bused to school as a child also made her extremely relatable," Wilson said. "I was glad that Sen. Harris challenged the former vice president on busing because that whole saga was a cathartic period in the history of separate but equal schools."

“Last week, 18 million Americans got to see what I have known about Kamala for some time. She is a once-in-a-lifetime leader. She exemplifies what global leadership is all about,” Rush said in a statement released by the Harris campaign, referring to the number of viewers who tuned in to the debates.

Harris is now trying to build momentum after her debate performance last week, with multiple recent polls showing a spike in support among Democratic primary voters.

“He has to say that I have evolved, as many people on other issues, that I now understand that, and how hurtful and harmful it was,” Meeks, who has not endorsed anyone, said of Biden. “It is very hurtful to African Americans, what took place. It's deep and systemic and still in this society.”

After the debate, Biden sought to clarify his position on busing, saying he believed the issue should have been decided at the local level and that courts, rather than the Education Department, should set the rules.

Before the exchange with Harris, Biden had already come under fire for remarks at a fundraiser in which he offered two segregationist senators as examples of people he could work with despite their disagreements.

A number of CBC members, long affiliated with the Clinton dynasty, flocked to her side even as Barack Obama was making strides in what would eventually lead to his history-making election as the country’s first African American president.

But the changing tides over the course of that hard-fought contest led to highly unusual cases of lawmakers shifting allegiances midstream.